In general, long CCFLs, EEFLs, or FFLs are required in large liquid crystal display (LCD) applications. These lamps demand high driving voltages. One method to drive long discharge lamps is to use a single inverter. However, it is very difficult to achieve uniform lamp brightness in this method. First, it is difficult to balance lamp currents on each end of the lamps. Sometimes, current balance transformers are added on each lamp end to balance the current of each lamp and achieve uniform brightness. However, this adds additional cost and complexity to the system. Also, if all discharge lamps are driven in a single-ended configuration, the voltage rating of the transformer's secondary winding would need to be too high to be realistically manufactured at a reasonable cost.
In order to achieve optimized performance and cost in large LCD panels, it is desirable to drive the discharge lamps with an improved system or method.